In the flamboyant company of peacocks and red admirals, dingy skipper butterflies (Erynnis tages), with their wing patterns as subdued as well-worn brown Harris tweed, might scarcely attract a second glance. I would not have noticed them if they hadn’t risen from beneath my feet and fluttered, moth-like, low over the spoil heap on the edge of Hawthorn quarry.

Despite their dowdy colour scheme, they are very picky about habitat. They need sheltered south-facing slopes clothed in low vegetation, with patches of bare ground where they can bask on chilly spring days, and plentiful supplies of bird’s-foot trefoil (Lotus corniculatus), their larval food plant.

These hummocks and hollows of magnesian limestone are so parched and devoid of mineral nutrients that much of the flora of cowslips, milkweed and carline thistle achieve only bonsai proportions, which suits the butterflies perfectly. Only bird’s-foot trefoil, with nitrogen-fixing root nodules that constitute a self-contained fertiliser supply, really flourishes here. This may be dingy skipper heaven, but even so there are rarely more than a few individuals on the wing during their brief April-June flying season.

I watched a male pursuing a female until she settled, allowing me to kneel down for a closer look. Seen from close range their wing patterns, like finely woven fabric in shades of brown and grey, are exquisite and provide almost perfect camouflage: take your eye off them for a moment when they settle on open ground and they can be hard to find again.

The butterfly shares this habitat with green tiger beetles, fast-running predators with iridescent emerald green wing-cases and sickle-shaped, toothed jaws. Once – and only once – I managed to catch one in my cupped hands. The pain in my palms was akin to being stabbed with a hot needle. Never again.

Today new adult tiger beetles had emerged from larval tunnels in the soft limestone where they had completed their development, and were mating in the same sunlit patches favoured by the dingy skippers. The beetles will spend their days hunting caterpillars, which may explain why dingy skippers are never very plentiful here, in what seems like an ideal habitat.